Method of and apparatus for compressing fluid.



R. SUCZEK MLTHOD OF AND APPARATUS FOR COMPRESSING FLU'ID. APPLICATION FILED mu 6. 1911.

1,283,593. Patented Nov. 5, 1918.

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gnuwuoz aA/jw bz R. SUCZEK. METHOD OF AND APPARATUS FOR commassmu FLUID.

APPLICATION HLED !ULY I6. 1911 Patented Nov. 5, 1918.

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ejector apparatus the ratio'of,con'iprcssion hr UNITED STATES PATENT OFFICE.

ROBERT SUCZEKpO F PHILADELPHIA, PEIi'NSYLVANIA, ASSIGNOE TO (1. H. WHEELER MANUFACTURING COMPANY, 01? PHILADELPHIA, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

METHOD OF AND APPARATUS FOR GOMPRESSING FLUID.

Application filed July 16, 1917.

To all whom'it may concern Be it. known that; I, Ronnn'r Socznu, a sub jeet of the Emperor of r mstria'Hnngary, residing in the city of Philadelphia. county of Philadelphia, and State of Pennsylvania, have invented certain new and useful lm-- provements in Methtals of and Apparatus for Compressing Fluid, of which the followin is a specification.

%'Iy invention relates to a method of and apparatus for compressing elastic fluid by operating thereon upon the ejector prinoiple in a plurality of stages by elastic motive fluid, such as steam.

It is the object of my invention to provide a method and apparatus for compre sing elastic fluid from a vacuum of 25 inches or higher, as measured on the mercunv column, to suitable higher pressure, as atmospheric pressure or higher, at. higl'ier efficiency than heretofore attainable. that is by reducing the amount of motive tluid per unit of elastic fluid compressed.

.The load upon an ejector, that is, the amount of'elastic fluid compressed. varies in practice over considerable range. \Vith av given steam or motive fluid consmnption and an increase in the load the absolute pressure at. the suction inlet of the ejector rises; for example, where more air is to be removed from a steam rondenser or the like with a girensteaip consumption the pressure in the condo ser will rise, that is, the vacuum will heco" e'ss. V M

I ha'w etound that in vacuum producing the first stage should be equal to or preferably greater than the ratio of compression in the second stage for all variations of load which more variations inthe initial pressure of the uni ue fluid to be compressed ranging over approximately one-sixth orless of the entire'range from zero absolute pressure to the pressure to which tli'eelastic fluid is conipressed. i

Accordingly, by. my invention, whatever the type ofithe ejector apparatus; I so proportion the total throat area of the nozzle or nozzles in the first; stage to the total throat area of the nozzleor nozzles in the second stage that in the first Stage there will be conowned more than five per cent. at the total motive fluid othoth stages. With this con- Specification of Letters Patent.

Patented Nov. 5, 1918.

Serial No. 180,873.

the pressure to which the elastic fluid is compressed. Through the remainder of the total range through \Vl'llClt tllt elastic fluid is com- 'iresscd. however. the relation of the ratios of compression in the two stages is reversed in that in the first stage the ratio of compression is less than in the second stage. I have found that. the most efficient operation of the apparatus is obtained when the ratio of compression in the first stage is equal to the ratlo of compression in the second stage for a load causing at the suetaon inlet of the first stage a vacuum of 25 inches or higher. or

,withinthe first sixth of the entire range from zero absolute pressure to the pressure to which the elastic fluid is compressed.

For an illustration of some of the forms my apparatus may take and for an illustration of some of the forms of apparatus suit able for carrying out my method, reference is to be had to the accompanying drawing, in which:

Figure l is a graphic representation of the relation between the ratios of the compres-' sion ratios of both stages-and pressures atth suction inlet of the first stage. ejector.

Fig. 2 is a sectional view parts in elevation, of double stage apparatus embodying my invention.

Fig. 3 is a horizontal sectional view illustrating the arrangement of nozzles in the first stage of H 2.

Fig. 4 is a ragnientarysectional View, partly in elevation, of nozzles and difi'user suitable for employment in my apparatus. and particularly in the first stage thereof.

Fig. 5-is a horizontal sectional View illus hating the arrangement of the nozzles of Fig. 4.

Fig. 6 is a vertical sectional \"l8\\\ partly in elevation. of. a modified form of double stage apparatus embodying my invention.

Referring to Fig. 1; G is a characteristic curve Whose ordinates are quotients 0b tained by dividing the ratios of com ression in the second stage by the simu taneous ratios of compression in the first stage, and whose abscissae are degrees of vacuum at the suction of the first stage expressed in inches of mercury column, referred to 30 inch barometer. The part of the curve 0 above the horizontal heavy line a and to the left of the point b refersto ratios of compression in the first stage which are greater than the simultaneous ratios of compression in the second stage, while all points of the curve to the right of point b and below the line refer to a reverse condition, in that in the second stage the ratios of COIIIIBSSIOII are greater than in the first stage. T n'oughout the curve C the total steam consumption of both stages is constant and the steam consumption of the first stage is a constant ercentage of the total steam consumed in both stages.

The curve (1, obtained from ohsca'vations of double stage apparatusembodyin' my H'i' vention, shows that for varying loar. s on the ejector apparatus causing in the suction in let of the first stage ejector a vacuum higher than approximately 26 inches, and with a given steam consumptionin the first stage of more than 5 per cent/of the total steam hr motive fluid consumption of both stages, the ratios of compression in the first stage are greater than in the second stage.

By increasing the pro ortlon of steam or motive fluid used in the rst stage the point 6, where the curve C intersects the line (1, moves toward the right and may reach at least as far as the point 0 corresponding with 25 inches of vacuuli or substantially one-sixth of the range atom zero absolute pressure to atmospheric gressure or higher.

To so proportion the ouble stage apparatus that the point b moves even farther to the right than the pointc is, I believe, of

' no advantage, in that forrvacua of less than 25inches single stage apparatus may be employed to greater advantage than double stage apparatus and athigher efiicien'cy.

The total ratio of compression of two stages of the ejector apparatus, that is, the ratio of the pressure at the discharge of the second ejector to the first stage suction pressure, for example when increasing the pressure of the air from 29 inches vacuum or 1 inch absolute to atmospheric pressure or 30 inches absolute, is 30. For such a total ratio of compression, the ratio of compression in each stage, when the ratio of compression in one stage is equal to that in the other, is the square root. of the total ratio of compression, and in this example approximately 5.47. And as the ratio of compression in the first stage iIlClBtlSQS above that in the second stage, the ratio of compression for this example will be in the first stage greater than 5.47, and the ratio of compression in the second'stage will be correspondingly smaller, the products of the ratios of compression in both stages equaling the simultaneous total ratio of compression.

In the example illustrated in Fig, 1, the two stage ejector apparatus is such that there is equality of the ratios of compression in both stages for a first stage suction pressure of 3.5 inches absolute. For such suction pressure, when the apparatus compresses the air to 30 inches absolute the total ratio of compression is 8.6, and the ratio of com ression in each sta e is the square root 0 8.6 or 2.9; and for a l suction pressures less than 3.5 inches absolute the ejector apparatus will operateLwith a ratio compression in the first stage greater than 2.9 and in the second stage less than 9.9, when compressing to 30 inches absolute.

y invention therefore comprises a method of and apparatus for producing and maintaining vacua of approximately 25 inches or higher and characterized by the fact that the ratio of compression in the first stage ejector is higher than the ratio of compression in the second stage, with a motive fluid consumption in the first stage which is more than 5 per cent. of the total motive fluid consumption of both stages. Under these circumstances the total motive fluid necessary for a given condition and load is less than has been attainable, so far as I am aware, with any previously practised method or apparatus.

It has been proposed to employ in the first stage of ejector apparatus a smaller ratio of compression than in the second stage in order that the amount of motive fluid delivered from the first stage into the second stage would be small and therefore require less motive fluid in the second stage, Wherein the motive fluid from the first stage must also be compressed to atmospheric pressure. The advantage in such method is more than compensated for by the fact that where a hlgh ratio of compression is resorted to in any stage, as the second, the amount of motive fluid required increases very rapidly with increase in ratio of com ression and increases also with the load, and the amount of motive fluid required to operate at high ratio of compression outweighs the advantage gained with low ratio of compression as in the first stage, in efl'ecting a saving 0% motive fluid in the second stage. In other words, the saving effected by using in the first stage relatively small amount of motive fluid and therefore small ratio of compression is more than counterbalanced when using in the first stage a'greater amount of,

motive fluid and a pression.

Accordingly by my invention I use in the first stage a greater amount of motive fluid, more than 5 per cent. of the total motive higher ratio of comfluid of both stages, and in any event an amount of motive fluid insuring a ratio of compression in the first stage higher than or equal to the ratio of compression in. the second stage when producing high vacuum, as above 25 inches.

In Fig. 2 is shown ejector apparatus embodying my invention and suitable for car-- rying out my method and is in general of well known construction comprising in the first stage a plurality of motive fluid nozzles N whose inlets communicate with the chamber d to which suitable motive fluid, such as steam under pressure, is delivered through the opening 2. These nozzles are in a chamher 7' havin the suction inlet 9 communicating with tfie condenser or other device in which high vacuum is to be maintained. The nozzles are directed toward the diffuser h which, in the example illustrated, discharges into the chamber 2', which may be a condenser in which the steam or motive fluid from the first stage injector is condensed, as well understood in the art. From the chamber '2' the elastic fluid to be compressed is delivered to the suction inlet j of the second stage comprising the nozzles N whose inlets communicate with a chamber d to which steam or other elastic motive fluid is delivered through the passage e. The nozzles N are directed toward the second stage diffuser It which discharges at is to atmosphnric or into any desired receptacle.-

lo adept this apparatus for carrying out my method and to embody my invention. however, I so proportion the areas of the throats T of the nozzles N of the first stage with respect to the areas of the throats T of the second stage that the sum of the areas of thefirst stage throats T shall be such that they uuitedly pass steam or motive fluid more than 5 per cent. of the total motive fluid used by the nozzles N and N ofboth stages. llnder such circumstances the ratio of compression in the first stage will be greater than or at least equal to the ratio of compression of the second stage when there is at the suction inlet 9 of the first stage a vacuum of 25 inches or higher. Vhen the amountof air or other elastic fluid entering at g varies, the vacuum at 5: will correspondingly vary. the vacuum rising as the amount of elastic fluid arriving at the suction inlet decreases. And for all varying loads causing at the suction inlet 9 a vacuum 'arying from 25 inches upwardly the ratio of compression in the first stage as slated. equal to or highr; than the ratio of compression of the second stage when the steam consumption by the first stage nozzles is more than 5 per cent. of the total steam consumption of both stages. under which circumstances the total steam consumption of the eject-or apparatus as described will be less than when in the first stage under like conditions the ratio of compression is less than the ratio of conlpression of the second stage.

It; will be undcrstoml that the chamber or condenser i may be used or not. as desired.

When the interstage condenser is employed the steam or condcnsable fluid dis charged thereinto from the diffuser i1. is roudensed, with the result that the amount of elastic fluid to be compressed by the second stage is reduced. VVbere such condenser is employed. the amount. of motive fluid consumed in the second stage may be reduced to substantially 50 per centum of that which is necessary therein in the case where no coudensation between stages takes place. There fore, where a condenser i is used and the consumption of steam in the second stage is thus reduced substantially one-half. the steam consumption in the first stage will still be more than 5 per cent. of the entire steam consumption, and will be a greater proportion of the total steam consmnption than in the case where the inter-stage condenser is not employed.

It will be understood that in either stage any suitable nozzle structure or arrangement may be employed.

For example. there may be employed the nozzle arrangement of Figs. 4 and 5. particularly in the first stage. There are in this case two circular series of nozzles X and a nozzle N at the center, the nozzles increasing in length from the outside of the group toward the center; that is. the nozzle outlets approach or extend into the diffuser structure farther and farther as they are positioned further and farther from the outside toward the center of the group.

It will be noted also as to Fig. 2 that the arrangement is similar in thatthe nozzles increase in length toward the center. This I have found of :ulvantagg particularly at the heavier loads. when using in the first stage a ratio of compression equal to or greater than the ratio of compression in the second stage. to insure steadiness of operation. that is, to prevent periodic fluctuations in the vacuum.

By such arrangement of Figs. .2 and -l the jets from the outer nozzles entrain by far the greater part of the elastic fluid to be compressed. and the jet from the central nozzle is particularly employed for compression purposes to deliver the mixture at high velocity to the throat m of the diffuser.

In Fig. 6 I have shown a modified double stage structure in which in the first stage there is used an ordinary type of ejector similar to that used in the first stage of Fig. 2. motive fluid or steam being delivered to the chamber (1 through the pipe u controlled by valve 0. The diffuser h of the first stage delivers the mixture of motive fluid and fluid to be compressed in divided streams through the passages p, p into the annular chambers compression less than the ratio of compression of the second stage, said predetermined value being within e range below inchrr mercury absolute.

5. The method of compressing elastic fluid, which consists in partially compressing the some by ejector action in each of two stages, and in the first stage cum-lining and compressing said elastic fluid by elastic motive fluid of such quantity as lo cause in the first stage n ratio of compression greater than the ratio of compression in the srwnd stage for all first stuge suction pressures less then a predetermined mlu and HS in eunufor all first stage suction pressures higher than said predrtermined, reiue :1 l'uiili; oil compression less than the ratio of compression of the second stage, said predetermined value being Within. u range from zero absolute pressure to approximately one-sixth of the pressure to which the elastic fluid is sour pressed.

(3. The method of compressing elastic fiuid in two stages from a pressure than 5 inches mercury absolute to substantially atmospheric pressure, which CUIlsisl'S in entraining ehd compressing in the first stage said elasticfluid by elastic motive fluid or such quantity as to cause in the first. stage a ratio of compression. greater than the ratio of compression in the second Stage. For all first stage suction pressures within =1 range below 5 inches mercury absolute, (mule-us ing the condensnhle liuid delivered From the first stage, and in the second stage we training and compressing: the uncoxulensed fluid by elastic motive fluid and delivering it at substantially eiuiosplwric pressure.

7. The method of rompirssing clnstir: fluid. in two stages from a pressure hrlew 5 inches mercury absolute to substantially a1 mospheric pressure, which consists in ontraining and compressing in the first stage said elastic fluid by elastic motive fluid of such quantity as to cause inlhe iii-st ratio of compression which is; equal to the ratio of compression in the s Ind r-ztuge for a. first; stage suctionpressure less than 5 inches mercury absolute and greater than the ratio of compression in the second stage for all first stage suction pressures in a range below said first named first stage suction pressure, condensing the condenseblc fluid delivered from the-first stage, and in the second-stage entraining and compressing the uneondrnsed fluid by elastic motive fluid and delivering it; at suhstzmtiully atmospheric pressure.

8. The method of compressing elastic fluid, which consists in partially compre ing the same by ejector notion in each of two stages, and in the first stage entruining and compressing suid elastic fluid by elastic motive fluid in excess of 5 percenturu of the total motive fl id consumed in both stages 7 1' it out lll ii u: the it.

stlilclure oi the second shill? that lllr who o1 cmuprvssion in ilie lire: l'uge is We ins than the ratio of emnprcssi u in the M wi l tage :md the nzotiw illllll phased llzrmlu'h the nozzle structure of the first stage is greater than 5 pereontuui of tin: nuuile luid consumed in both mun-1i.

ill. Multistage cjert r upper-anus emuprising two ell-chm connected in series, .unl such comprising nozzle and dili'mer structure, the total throat urea of lhr .liiUX/flll structure of the first stage being Snell iliut llio ratio of COHIPIQSHUII in the first singlinnot less than the ratio of coiuplwauon in the second stage.

11. Two-stage ejector apparatus for (four pressing elastic fluid to substantially u? illnlrw e1 e pressure, comprising the circle iii-c end diffuser structure the total three of the nozzle rili'leturo in the tint Elwin lwiug =1 oh that the ratio of cum n-w i the ii mi in series and nch comprising a (romp sion in the err-curl stugc l sis uclwn pussure-x within 45 run 5 iu iies mercury absolute.

Mailtiesiege ejectoruppaiulus so mg two cit-(tors connected in series and l comprising n zzle and diffuser strolls the nozzle throat arms of the two s being so proportioned with respect to r ch oiiior that with varying first stage suction pressure the ratio of compression in thriin t stage varies llhrough values sweeter than and les than the siznullunenue relic of emnprrssion in the second stage.

15 -3. Multis ngepjcrtorapparatus LUll'lfll'lilug two cjert'ors connected in series and each hill ratio of compression in the second stage for any first stage suction pressure Within a range below inches mercury absolute.

24. Two-stage ejector apparatus for compressing elastic fluid from an absolute pressure less than 5 inches of mercury to substantially atmospheric pressure comprising two ejectors connected in series and each comprising nozzle and diffuser structure, the total throat area of the first stage nozzle structure being so proportioned with respect to the total throat area of the nozzle 25. Two-stage ejector apparatus for compressing elastic fluid to substantially atmospheric pressure comprising two ejectors connccted in series with each other and each comprising nozzle and diffuser structure, means between said ejectors for condensing flu-id discharged from the first ejector and discharging uncondensed fiuid to the, second ejector, the total throat area of the nozzle structure of the first ejector being so proportioned with respect to the total throat area of the nozzle structure of the second ejector that the ratio of compression in said first ejector is greater than the ratio of com-i pression in the second ejector for all first stage suction pressures Within a range below 5 inches mercury absolute.

In testimony whereof I have hereunto affixed my signature this 13th day of July,

ROBERT SUCZEK. 

